If you want to run that, it will run fine.
However, with a Wrath/Starfire cast on the mob, the Curse of the Elements is not needed.
Or alternatively, with CotE on a mob, the Boomkin doesn't bring that much to the table.

You can use drums for an 80% as good, Mark of the Wild.
You lose out on battle rez and innervate.
But adding say another Shaman gets you a 3rd set of totems, which makes you almost immune to fear in PvE.
Or adding an arcane mage gets you food/water, ports and far superior dps without needing to manage Eclipse.

My main PvE team is a Prot Paladin, Demo Warlock and 3x Elemental Shaman.
If I wanted a dedicated healer, it would be a toss up between a Disc Priest and a Resto Druid, in the place of one of the shammies.

With the toons mentioned by J6mpsikas above, I'd respec them to:
- Prot Pally (tank)
- Elemental Shaman x2
- Destro Lock
- Resto Druid.